Nullability.java

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package org.jooq;

/**
 * An enum that specifies the nullability of a {@link DataType}.
 *
 * @author Lukas Eder
 */
public enum Nullability {

    /**
     * The data type is explicitly nullable.
     */
    NULL,

    /**
     * The data type is explicitly not nullable.
     */
    NOT_NULL,

    /**
     * Default behaviour for data types.
     * <p>
     * The interpretation of this value depends on the context in which a
     * {@link DataType} is used:
     * <ul>
     * <li><code>CREATE TABLE</code>: The data type is implicitly nullable (or
     * explicitly, if the underlying database does not support implicit
     * nullability or defaults to implicit non-nullability).</li>
     * <li><code>ALTER TABLE .. ALTER COLUMN .. SET TYPE</code>: The data type's
     * nullability will not be modified.</li>
     * </ul>
     */
    DEFAULT;

    /**
     * Get the explicit {@link Nullability} corresponding to a boolean value.
     */
    public static Nullability of(boolean nullability) {
        return nullability ? NULL : NOT_NULL;
    }

    /**
     * Whether this nullability encodes an explicitly or implicitly nullable type.
     */
    public boolean nullable() {
        return this != NOT_NULL;
    }
}